If you have Photoshop Elements 13/13.1, Photoshop Elements 13/13.1, Elements Organizer 13/13.1, the nef files from your Nikon D5500 should be supported with the Camera Raw 9.0 which is the latest Camera Raw version for those versions. See an opened projects Help Menu/Updates.
You get that type of information from links such as
Note that the last link needs to be updated by Adobe for Camera Raw 9 for version Elements 13/13.1.
What is your program - Photoshop Elements 13/13.1 or Premiere Elements 13/13.1? Editing in the Camera Raw dialog is done if you have Photoshop Elements. The Camera Raw only enables raw image files and dng files importing into a Premiere Elements video project.
I have already responded to your question in post 1 at 3:31 pm. The forum is having a problem today with routine posts being moderated before appearing.
My post contains full information on your use of Nikon D5500 files in Photoshop Elements 13/13.1, Premiere Elements 13/13.1, and Elements Organizer 13/13.1.
You should have no problems importing these nef files as source media into a Premiere Elements 13/13.1 project nor editing them in Camera Raw 9.0 plug in if you have Photoshop Elements installed.
I am hoping that this post makes it through any filters. My post 1 should show up sooner or later.
Any questions or need clarification, please do not hesitate to ask.